With styling reminiscent of the brand's Carrera GT hero car, the 918 Spyder draws power from a hybrid system made up of a 373kW V8 and two axle-mounted electric motors offering a combined output of 160kW.

Thanks to the V8 and the additional all-wheel-drive poke provided by the electric motors, the 918 Spyder reaches 100km/h in 3.2 seconds, on its way to a top speed of 320km/h.

Being a hybrid however, fuel economy is the big question: According to Porsche, its new green machine uses just 3.0 l/100km on the combined cycle, making it more efficient than the Toyota Prius. Emissions are even lower, releasing just 70g/km of CO2.

Like the Prius, the 918 Spyder is a parallel hybrid, able to run on the combined power of petrol and electricity, or via either power source on its own. Four driving modes allow the driver to select between varying combinations of performance and efficiency.

In the all-electric E-Drive mode, the 918 Spyder offers a range of 25km. Hybrid mode is described as the best option for day-to-day driving, while Sport Hybrid offers a mix of optimum efficiency with a little extra power.

Race Hybrid utilises the full power of both the V8 engine and the electric motors, throwing efficiency out the window. According to Porsche, Race Hybrid mode will get the 918 Spyder around the Nordschleife in less than 7:30 minutes.

Like the Porsche 911 GT3 R Hybrid revealed last month, the 918 Spyder also offers a 'push-to-pass' button, feeding additional power to the wheels for overtaking efforts.

While the 918 Spyder isn't scheduled for production in the near future, Porsche says it represents "an essential milestone in Porscheís strategy on the way to genuine electric-mobility".